Safety valve for heaters



June 9, 1931.

E. R. CLARK SAFETY VALVE FOR HEATERS Filed Aug. 24, 1928 Patented June 9, 1931 UNITED. STATES EARL R. CLARK, OF HIGHLAND PARK, MICHIGAN SAFETY VALVE FOR HEATERS Application filed August 24, 1928. Serial No. 801,768.

The present invention relates to safety devices for ,hot water systems for household pur oses.

eretofore, in household water heaters, it frequently happens that the occupant forgets to turn out the burner under his heater with the result that the water in his storage tank becomes highly heated and frequently is converted to steam which becomes forced back into the water supply line as far back as the water meter. As the latter device is more or less delicate mechanism, this quite hot water or steam will seriously affect its operation, if it does not entirely ruin it.

Among the objects of the resent invention is to relieve the system of this objection and provide means for preventing the injury to the meter and provide the system with a safety device which does not otherwise afi'ect ea its 0 eration.

0t er objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings, in which Figure 1 is a diagrammatic elevation of a water heater and storage tank with the present device applied.

Figure 2 is a section of the safety device on line 2-2 of Figure 1.

Figure .3 is a section on ure 2.

In the drawings, the storage tank for hot water is indicated at 10 with the gas heater at 11 supplied with gas through pipe 12 and with cooler water through pipe 13, the heated water passing out through pipe 14 to the top of the tank 10.

Cold water is supplied to the tank through pipe 15 leading from the water meter indicated at 16 and this pipe extends into the top of tank 10 to near the bottom thereof. Hot wzater is drawn from the tank through pipe 1 Without the present device, when steam '30 line 3-3 of Fig- 50 action, a by-pass 20 is provided adapted to is formed in the upper part of the tank 10,

- injury to the meter 16.

establish communication between the cooler Water pipe 13 and the heated water pi e 14 and in this pipe is placed the safety evice shown in Figure 2 and indicated in Figure I 1 at 21. '5;

The safety device 21 as shown in Figure 2 consists of a housing member provided with threaded bosses 22 for attachment to the pipes forming the by-pass 20. This casing is also provided. with the lateral boss 23 60 which is perforated and connects with the opening 24 in an interior boss 25. This passage 24 extends into boss 25 and opens tothe interior of the casing, the inner end thereof being formed into a valve seat 26. Boss 25 is on also provided with a plurality of openings through which pass guides 27. These guides abut at one end, the end plate of a thermostat 28 shown in the form of a metallic bellows. The other ends of the guide press against a to valve 30 which is carried upon a stem 31 extending into a threaded guide 32 which in turn is provided with a stem .33 extending from the casing at one end thereof. A suitable stufling box 34 is provided for the stem ?3 33 which latter is also provided with a squared end 35 so that it may be adjusted in the casing.

Between the guide member 32. and valve 30 is a spring surrounding the valve stem 31 as and adapted to exert pressure thereon.

The thermostat 28 rests against the end of the casing opposite to the guide 33, which end may consist of a threaded lug 41.

The safety device when place in the po- 35 sition indicated in Figure 1 that is substantially at the level of or slightly above the discharge end of the water supply pipe, and; adjusted to provide for opening valve 30 through expansion of the thremostat and consequent to compression of spring 40, will prevent the passage of steam or water at near boiling temperature back into pipe 15' as it may be adjusted to open the valve at any desired temperature. When the valve is 05 opened, the hot water or steam, as the case ma be, will discharge through passage 24 an into a suitable drain pipe 50 connected to the casing at boss23 and thereby prevent New having described the invention and the'preferred form of embodiment, it is to be understood that the said invention is to be limited not to the specific details herein de scribed and illustrated, but only by I the sco e of the claim which follows.

claim I In a hot water heatin system, a storage tank having a cold water inlet leading to and opening ad acent the tank bottom, and a hot water outlet in the to of the tank, a hot water heater on the si e of the tank, a pi e leading from the bottom of the tank to t e bottom of the heater, a pipe leading from the top of the heater to the upper portion of the tank, a. by ass ipe connecting the latter two pipes, an a t ermally sensitive relief valve in said by pass pi e near the lower end thereof and eonstructe to discharge a portion of the tank contents which has accumulated in said tank and spread thru said by pass pipe, when the tank contents have exoeeded a predetermined temperature and not before.

' EARL R. CLARK. 

